Proton charges, indicating

The reason for these discrepancies may arise from the very important discovery that a single acidity function cannot describe the protonation of indicator bases of even the same charge type12-19 and Katritzky et al.19 have emphasised that this renders the attempt by Bunnett20 to obtain a more satisfactory diagnosis of the A-l, A-2, and A-SE2 reactions by the use of w and w values less reliable than it at one time appeared to be. 

Titration curves of cytochrome c (Fig. 30) indicate that the cosolvent induces a significant change in the acidic paH range with a variation in the net proton charge, ZH, of 0.6 unit at paH 6.0. 

The lack of coincidence between CIP and lEP of (hydr)oxides and related materials indicates the presence of strongly adsorbing species, added intentionally or present as impurities. Specific adsorption induces shifts in the lEP on the one hand and in the point of zero proton charge on the other in two opposite directions. When a shift in the CIP and lEP is addressed, the pristine PZC of given material (cf. Tables... 

Calculations have revealed that the proazaphosphatrane bases are approximately equal in thermodynamic basicity to the Schwesinger P2 phosphazene bases (Table 2.14). The RHF/ 6-3IG calculations of proton affinities indicate that phosphazene (Z = NH) and phosphorus ylide (phosphorane, Z = CH2) counterparts (146 and 145) are stronger than the parent Verkade superbase 139. Higher basicity is associated with the higher degree of delocalization of the positive charge in the protonated iminophosphoranes and phosphorus ylides as a result of the more electropositive character of phosphorus atom [67]. On the other hand, phosphoms oxides 147 and 150 are weaker than 139, but still above the superbasicity borderline. The strained polycycles 138, 149 and 148, as representatives of superbases... 

In order to find out which of the three nitrogens of this triazole ring is protonated, semiempirical calculations by the AMI method were performed. Comparison of the chemical shifts of the carbon atoms and the theoretically obtained electronic charges indicates that nitrogen 11 happened to be protonated [12], Taken together, the above mentioned value can be attributed to nitrogen 26. 

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